Ds is just 3, he's happy and I think you could describe him as bang on average in development across the range. However he's started school nursery and immediately I've got the concern he plays alone. Two private nurseries raised this too.
I was there today, it's as I see at playgroups. He's very happy, lots of getting engrossed with toys (he has a range of interests, could be animals, cars, fire engines, water, paint..if we'd been to a farm it could be animals for example). He plays alone, but has no negative interaction, if another child joins him he doesn't snatch, can share, often handing them a toy if they ask. His language is average for his age, communicates needs and follows nursery instructions well. At home he has the odd temper tantrum but is generally a very mild 'good' child. He stops activities if asked and can be easily distracted. He doesn't object to others at all. Outside nursery he has 3-4 friends he plays with well, role play, running...all the usual. He's known these a long time and they are the few kids he picked out over the years through playgroups/ park etc as special friends. They are quite diverse in age, gender and ethnicity, just simply kids who get on.
Now I can't see a problem at all. He's very happy all day. However this is the third nursery to home in on him and try to develop play skills and raise concerns. The only time he has ever been upset at nursery is after extended forced interaction, for example over and over being dragged over to play dolls or another non-interest with girls who are very ahead for their age in language or pairing with kids who have no language at all.
Now am I missing something? Was IBU today to ask nursery to leave him be and stop telling me he plays alone? I went in for an hour and I can't see the issue at all. He's not obsessive/ follows instructions/ happy/ learning/ joins in group time etc.